Resultados preliminares sobre o comportamento de cultivares e hídridos de milho normal em solos de cerrado na região de Brasília.

Resultados obtidos em condições de campo durante o ano agrícola de 1975/76, sobre o comportamento de 30 cultivares e híbrido de milho

Phosphorous flow analysis and resource circularity at the province level in north Italy

Phosphorus is an essential element for living organisms, but its unequal distribution combined with the current anthropogenic activity make it a critical resource. To decrease the risks of future shortages, new techniques to manage phosphorous are needed to be mainstreamed under a Circular Economy approach to boost a sustainable transition. A full characterization of flows and stocks is necessary to measure the contribution of secondary materials to meet the overall demand in a system and support decision-making process towards potential improvements. This understanding is determinant for a successful implementation of phosphorous recovery at the regional level, where site-specific conditions dictate local constraints. In this study, material flow analysis has been applied to characterize the 2020 phosphorous cycle in the Province of Rimini (Italy) and the State of San Marino, which are served by a wastewater treatment plant with a 560,000 person-equivalent capacity. Our model shows that, about 236 ± 23 t P entered the system, while 155 ± 14 t P left it, resulting in a net accumulation of 81 ± 21 t P, mainly located in soil for crop production, water bodies, and sedimentation due to dissipative flows. The greatest potential for phosphorous recovery is embedded into the digested sludge from the wastewater treatment plant, which would ideally meet 96% of the annual local demand of mineral fertilizers. However, this flow is currently disposed of by landfilling. Further technical, economic, environmental, and regulatory valuations are ultimately needed to build a positive business case to recover phosphorous in the region

Characterization of the bacterial communities of aerobic granules in a 2-fluorophenol degrading process

Aerobic granular sludge constitutes a novel technology for wastewater treatment. This study focused on the effect of 2-fluorophenol (2-FP) shock loadings on the microbial community diversity present in aerobic granules before and after inoculation with a bacterial strain able to degrade 2-FP, Rhodococcus sp. strain FP1. After bioaugmentation, apart from strain FP1, five culturable bacteria were isolated from the 2-FP degrading granules, belonging to the following genera: Serratia, Chryseobacterium, Xanthomonas, Pimelobacter and Rhodococcus. The latter two isolates are able to degrade 2-FP. Changes in the aerobic granules' bacterial communities related to 2-FP shock loadings were examined using denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene pool. Numerical analysis of the DGGE profiles showed high diversity with an even distribution of species. Based on cluster analysis of the DGGE profiles, the bacterial communities present in the aerobic granules changes were related to the sampling time and the 2-FP concentration fed.publishersversionpublishe

Bacterial community dynamics in a rotating biological contactor treating 2‑fluorophenol‑containing wastewater

One of the main factors affecting the performance of rotating biological contactors (RBC) is the biofilm characteristics. Therefore, a deep understanding of the microbial population dynamics and structure of the biofilm is mandatory if optimization of organic matter and nutrients removal is targeted. This study focused on the effects of organic shock loads of 2-fluorophenol (2-FP) on the microbial diversity present in an RBC biofilm. The RBC was seeded with activated sludge from a conventional wastewater treatment plant and was operated during 496 days. During the first 126 days, the RBC was subjected to intermittent 2-FP shocks of 25 mg l(-1) and no degradation occurred. Therefore, the reactor was subsequently augmented with a 2-FP-degrading strain (FP1). Afterwards, the RBC had a stable performance when subjected to 2-FP shocks up to 50 mg l(-1) and to a starvation period, as indicated by removal of the compound. Denaturing gradient gel electrophoresis (DGGE) revealed large shifts in microbial communities present in the first and fifth stages, although no clear relation between the sample collection time and spatial factor was found. Phylogenetic affiliation of some predominant members was assessed by direct sequencing of correspondent DGGE bands. Affiliations to alpha-, beta- and delta-Proteobacteria were found. Several bacterial strains isolated from the reactor showed capacity for 2-FP degradation. Strain FP1 was successfully recovered from the biofilm by plating and by DGGE, reinforcing that bioaugmentation was successfully achieved.info:eu-repo/semantics/publishedVersio

Bioaugmentation of a rotating biological contactor for degradation of 2-fluorophenol

The performance of a laboratory scale rotating biological contactor (RBC) towards shock loadings of 2-fluorophenol (2-FP) was investigated. During a period of ca. 2 months organic shock loadings of 25 mg L-1 of 2-FP were applied to the RBC. As no biodegradation of 2-FP was observed, bioaugmentation of the RBC with a 2-FP degrading strain was carried out and, along ca. 6 months, organic shock loadings within a range of 25-200 mg L-1 of 2-FP were applied. Complete biodegradation of 50 mg L-1 of 2-FP was observed during operation of the reactor. The RBC showed to be robust towards starvation periods, as after ca. 1 month of non-supply of the target compound, the reactor resumed 2-FP degradation. The inoculated strain was retained within the biofilm in the disks, as the 2-FP degrading strain was recovered from the biofilm by the end of the experiment, thus bioaugmentation was successfully achieved.info:eu-repo/semantics/acceptedVersio

Treatment of wastewaters contaminated with heavy metals using aerobic granules in a sequencing batch reactor

info:eu-repo/semantics/publishedVersio

Wastewater valorization: Practice around the world at pilot-and full-scale

LA/P/0140/2020Over the last few years, wastewater treatment plants (WWTPs) have been rebranded as water resource recovery facilities (WRRFs), which recognize the resource recovery potential that exists in wastewater streams. WRRFs contribute to a circular economy by not only producing clean water but by recovering valuable resources such as nutrients, energy, and other bio-based materials. To this aim, huge efforts in technological progress have been made to valorize sewage and sewage sludge, transforming them into valuable resources. This review summarizes some of the widely used and effective strategies applied at pilot-and full-scale settings in order to valorize the wastewater treatment process. An overview of the different technologies applied in the water and sludge line is presented, covering a broad range of resources, i.e., water, biomass, energy, nutrients, volatile fatty acids (VFA), polyhydroxyalkanoates (PHA), and exopolymeric substances (EPS). Moreover, guidelines and regulations around the world related to water reuse and resource valorization are reviewed.publishersversionpublishe